London, England (CNN) -- There are "compelling reasons" to believe the Israeli government was responsible for forging British passports used in a plot to kill a Hamas leader in the United Arab Emirates earlier this year, British Foreign Secretary David Miliband said Tuesday.

"Such misuse of British passports is intolerable," Miliband said, adding that the fact that Israel was an ally of the United Kingdom "only adds insult to injury."

The passports were "copied from genuine British passports" in a "highly sophisticated operation," indicating a government was behind it, Miliband told the House of Commons.

Britain's Serious Organised Crime Agency concluded that the 12 British people whose passports were cloned where "wholly innocent victims of identity theft," the foreign secretary said.

The UK expelled an Israeli diplomat and changed the advice it gives its citizens about traveling to Israel as a result of the scandal, Miliband said. He did not name the diplomat or say what rank the envoy held.

"The UK had absolutely no advance knowledge of what happened in Dubai nor any involvement whatsoever in the killing" of Mahmoud al-Mabhouh, he said.

Israeli Foreign Minister Avigdor Lieberman complained that the Israelis "have not been given any evidence pointing to Israel's involvement in the affair."

"We attribute great importance to our relations with Great Britain," he said. "We maintain several different and sensitive dialogues with the UK, and we regret the British decision."

French authorities also have opened an investigation into the alleged use of forged documents, the Paris prosecutor's office said Tuesday.

Suspects in the killing allegedly used four doctored French passports, the prosecutor said in a written statement.

"Further investigation has revealed that these four passports were actually false as the photos did not correspond to the names appearing in each document," the statement said.

Al-Mabhouh, a founding member of Hamas' military wing, was found dead January 20 in his Dubai hotel room. Police believe he was killed the night before, allegedly by the secretive Israeli foreign intelligence unit Mossad.

Two sources told CNN earlier this month that the number of identified suspects in al-Mabhouh's death was up to 27. Of them, 26 were carrying European or Australian passports, authorities have said. The sources -- an official familiar with the investigation and a police source -- did not say which nation issued the passport used by the 27th suspect.

The 27 suspects are believed to have acquired false passports to travel to Dubai for the killing, then scattered to several far-flung locations afterward. But Lt. Gen. Dahi Khalfan Tamim, Dubai police chief, has said not all the suspects had fraudulent passports -- "We know some of the names are real."

Interpol, the international police agency, has issued "red notices" to help search for the suspects. The notices are not international arrest warrants, but are a way of alerting police forces around the world that the suspects are wanted by United Arab Emirates authorities.

Police have said toxicology results show al-Mabhouh was injected with succinylcholine, a drug used to relax muscles during surgery or as an anesthetic, before he was suffocated. Signs indicated that al-Mabhouh resisted as he was being suffocated, police said.

Al-Mabhouh's family members were told earlier that police had found blood on a pillow. Authorities have also said the killers left some of al-Mabhouh's medication next to him in an apparent effort to make the death appear natural. But "the medication left next to him in the room has nothing to do with the killing," Tamim has said.

Tamim told CNN last month that he is "100 percent sure" Mossad was responsible. "The Mossad needs to be ashamed of its actions," he said. "They sent 26, 27 persons to assassinate one man who was involved in the capturing and killing of two Israeli soldiers."

Hamas has said al-Mabhouh was behind the 1989 deaths of the Israeli soldiers.

Israel has a stated policy on security matters of neither confirming nor denying involvement. Lieberman, however, told Israel Army Radio earlier this month, "There is certainly no reason to think that the Mossad and not some other intelligence agency of another country operated there."

The total of 27 suspects does not include two Palestinians arrested in Jordan and returned to Dubai. Tamim said one is not believed to be directly involved in al-Mabhouh's death, but "he is wanted by one of the Palestinian factions in the Palestinian territories and he is sentenced to death and that's why we will extradite him." He declined to discuss anything about the other Palestinian.

CNN's Guy Azriel in Jerusalem and Niki Cook in Paris, France, contributed to this report.